Improvement in hot-blast apparatus



EEie,

JONAS J. PIERCE, OF SHARPSVILLE, PENNSYLVANIA.

IMPROVEMENT IN HOT-BLAST APPARATUS.

Specification forming part of Letters Patent No. 103,923, datcd June 7, 1870.

T0 all whom it may concern:

Be it known that I, JONAS J. PIERCE, of Sharpsville, in the county of Mercer and State 4of Pennsylvania, have invented a :new and useful Improvement in Hot-Blast for Furnaces 5 and I do hereby declare the following to be a full, clear, and exact description thereof, reference bein g had to the accompanying drawing, forming part of this specification, in which- Figure l is a side elevation of a hot-blast stove with my improvement. Fig. 2 is a top view. Fig. 3 is an end elevation, and Fig. et is a detached representation of one of the shoes used for connecting` the siphon-pipes.

In the several iigures like letters denote similar parts.

In hot-blaststoves used for heating a blast of air for blast-furnaces and other purposes, the pipes through which the current of air is passed in order to heat it are exposed to a high heat, and are thereforeliable to warp and crack, and, as the apparatus consists of a system of siphon -pipes placed vertically in a h eatin g-chamber, the crackingor displacement of one siphon-pipe disables the whole apparatus. It is therefore very important to construct the connections or return-pieces which support the lower ends of the Siphon-pipes in such manner as to diminish the liability of the pipes and connections to warp and crack, and to enable a defective pipe to be easily and expeditiously removed. The ordinary mode of supporting and connecting the system of pipes for heating air in such stoves is to have a continuouslongitudinal trunk or pipe of iron placed horizontally in the combustion-chamber of the stove, with apertures for the passage of the blast upinto the siphon-pipes, surrounded by sleeves or flanges to receive the lower end ofthe pipes. This enables the vertical siphonpipes to be removed and replaced by others, when they are disabled, without serious detention or derangement of the other pipes in the system; but as the Siphon-pipes are shaped like an inverted A, with a semicircuiar elbow at top, the heat tends to force the extremities of the pipes apart, and, as these are set in a continuous iron trunk, there is no sufficient provision for such expansion and contraction as takes place in the Siphon-pipes. They are therefore very apt to crack in a short time.

But this ordinary construction makes no provision for remedying any breakage of the horizontal supporting and connecting trunk without removing all the Siphon-pipes, and the replacement of this horizontal trunk therefore involves the cessation of the hot blast for a long time, and the consequent serious inconvenience and loss incident to a stoppage of the works.

To remedy this evil and permit of a speedy repair of the hot-blast apparatus, as well as to guard against the liability to deran gement and breakage of the aipparatus, is the object of my improvement, which consists in the substitution for a continuous horizontal metallic pipe or trunk, connecting and supporting the vertical Siphon-pipes, of a separate and detachable shoe or pedestal, forming the base and support of two adjoining Siphon-pipes, one leg of each Siphon-pipe resting on a different pedestal from the other leg, such shoes or pedestals being so constructed as to be easily and speedily detached and replaced by a new one without disturbing the other pipes or pedestals in the system.

In the accompanying drawing, at a is the stove, a being the combustion-chambers. b b are gas-fines, in which gas is conveyed to the combustion-chambers to heat the chamber. c c are the siphon-pipes, made of east-iron and of any desired construction, either in one piece or connected together by anges or sleeves at the elbows at top. -These Siphon-pipes are placed in systems, c c c, Src., in parallel rows, asv seen in Fig. 2, the lower extremity of the `irst siphon-.pipe in each system connecting with the horizontal cylinder c, through which thef cold air is admitted into the apparatus, and the last pipe in each system connecting with a cylinder, f, at the other end of the stove, into which the heated airis received from all the systems, and from which it is passed to the blast-furnace. The cylinders e and f are placed externally to the heatingstove.r

In the space between each furnace a a are placed the shoes or pedestals h, so as to be surrounded on two sides by the walls of the furnace, and protect them from t-he heat as much as possible but they are not surrounded so closely by the walls as to prevent their moving lengthwise to accommodate the expansion and contraction of the siphon-pipes. The pedestals h are placed on transverse iron rollers 'e' i, so that they may have a level foundation, and yet be able to move easily within the range of the space formed by the brick walls surrounding them, as seen in Fig. l. The pedes- Atals are made of cast-iron, each pedestal bein g a separate piece.

They consist of a semicircular return-piece or elbow of cylindrical pipe h, of the same diameter at each end 'as that of the Siphon-pipes which it is to be connected with.

A Hat base-piece, k, is connected with the curved return -piece h by a lweb, Z, which extends from the base k to the return-piece h all around the outer line of the curved part of the piece h, and is cast in one piece with the base 7c and return-piece'h. Thus constructed, these pedestals are very strong, and much less liable to crack than they would be but for the web extending, as described, all around the curved portion of the return-piece h and connectin g with the base 7c.

The extremity of one leg of a siphon-pipe, c, is placed on the top of one leg of the re turn-piece h, so that their edges coincide all round, and a sleeve, m, is slipped down the Siphon-pipe until it covers the joint and keeps the Siphon-pipe in place, as seen in Fig; 1.

As shown in the drawing', Fig. l, each pedestal supports only one leg of a siplion -pipe and the adjoining leg of the siphon-pipe next to itin the series.

When necessary to remove one of the pedestals or any of the siphon-pipes, it is only necessary to raise the sleeves m, when either the pedestal or pipe is free to be removed without involving the removal or replacement of any other part or parts of the apparatus.

By my arrangement the current of air iiows uninterruptedly through each series of siphonpipes, not being impeded by any unnecessary friction, or by having to pass at the bottom of each siphon-pipe into another pipe or trunk, the shape and internal capacity of which differ from that of the Siphon-pipes, thus giving a larger area of air-passage.

Another advantage is the increased amount of heating-surface afforded by the shape and construction of the separate pedestals over that afforded by the ordinary device for connecting the Siphon-pipes.

Having thus described my improvement, what I claim as my invention, and desire to secure by Letters Patent, is-

1. The detachable metallic pedestal or shoe for supporting and connecting the lower ends of Siphon-pipes in hot-blast ovens, constructed substantially as described. y

2. Connecting the lower ends of siphon-pipes in hot-blast ovens by means of elbows or return -pieces of pipe, having a basey and connecting-web, substantially as and for the purpose hereinbefore described.

In testimony whereof I, the said JONAS J. PIERCE, have hereunto set my hand.

JONAS J. PIERCE.

Witnesses:

A. S. NIoHoLsoN, G. H. CHRIsrY. 

